Effects of dexmedetomidine or methylprednisolone on inflammatory responses in spinal cord injury

Background The aim of this study was to compare the anti-inflammatory response of methylprednisolone and the alpha 2-agonist dexmedetomidine in spinal cord injury (SCI). Methods Twenty-four male adult Wistar albino rats, weight 200-250 g, were included in the study. The rats were divided into four groups as follows: the control group (n: 6) received only laminectomy; the SCI group (n: 6) with trauma alone; the SCI+methylprednisolone group (n: 6) with trauma and 30 mg/kg methylprednisolone, followed by a maintenance dose of 5.4 mg/kg/h; and the SCI+dexmedetomidine group (n: 6) with trauma and 10 mu g/kg dexmedetomidine treatment intraperitoneally. Twenty-four hours after the trauma, spinal cord samples were taken for histopathological examination and serum samples were collected for interleukin-6 (IL-6) and tumor necrosis factor (TNF)-alpha measurement. Results TNF-alpha (P=0.009) and IL-6 (P=0.009) levels were significantly increased in the SCI group. TNF-alpha and IL-6 levels were significantly decreased with methylprednisolone (P=0.002, 0.002) and dexmedetomidine (P=0.002, 0.009) treatment, respectively. Methylprednisolone and dexmedetomidine treatment reduced neutrophils' infiltration in SCI. Conclusions The current study does not clarify the definitive mechanism by which dexmedetomidine decreases inflammatory cytokines but it is the first study to report the anti-inflammatory effect of dexmedetomidine in SCI. Further studies are required to elucidate the effects of dexmedetomidine on the inflammatory response.